Flowable polyester molding compositions with ASA/ABS and SAN

ABSTRACT

A thermoplastic molding composition, comprising 10 to 98.99% of a thermoplastic polyester, 0.01 to 20% of a hyperbranched polycarbonate, and/or hyperbranched A x B y  polyester, wherein A x  and B y  are different monomers and indices x and y are functional groups in A and B, x is at least 1.1 and y at least 2.1; 1 to 60% of a graft polymer comprising 20 to 80% of a graft base comprising an elastomeric polymer based on alkyl acrylates, 20 to 80% of a graft of 60 to 95% of styrene or of substituted styrenes of formula 1 
                         
R is an alkyl radical or hydrogen, R 1  is an alkyl radical, n is 1-3, and 5 to 40% by weight of an unsaturated nitrite, 0 to 60% of a copolymer comprising, 60 to 95 of styrene and/or substituted styrenes of formula 1, 5 to 40% of an unsaturated nitrile, 0 to 60% of other additives.

This application is the National Phase of International Application No.PCT/EP2005/008341 filed on Aug. 2, 2005; and this application claimspriority to Application No. 102004038976.4 filed in Germany on Aug. 10,2004 under 35 U.S.C. §119; the entire contents of all are herebyincorporated by reference.

Description

The invention relates to thermoplastic molding compositions, comprising

-   -   A) from 10 to 98.99% by weight of at least one thermoplastic        polyester,    -   B) from 0.01 to 50% by weight of    -   B1) at least one highly branched or hyperbranched polycarbonate        having an OH number of from 1 to 600 mg KOH/g of polycarbonate        (to DIN 53240, Part 2), or    -   B2) at least one highly branched or hyperbranched polyester of        A_(x)B_(y) type, where x is at least 1.1 and y is at least 2.1,        -   or a mixture of these,    -   C) from 1 to 60% by weight of at least one graft polymer,        composed of        -   c₁) from 20 to 80% by weight of a graft base composed of an            elastomeric polymer based on alkyl acrylates having from 1            to 8 carbon atoms in the alkyl moiety and having a glass            transition temperature below 10° C.        -   c₂) from 20 to 80% by weight of a graft composed of        -   c₂₁) from 60 to 95% by weight of styrene or of substituted            styrenes of the general formula I

-   -   -   -   where R is an alkyl radical having from 1 to 8 carbon                atoms or a hydrogen atom, and R¹ is an alkyl radical                having from 1 to 8 carbon atoms, and n is 1, 2, or 3,                and

        -   c₂₂) from 5 to 40% by weight of at least one unsaturated            nitrile,

    -   D) from 0 to 60% by weight of a copolymer composed of        -   d₁) from 60 to 95% by weight of styrene or of substituted            styrenes of the general formula I, or a mixture of these,        -   d₂) from 5 to 40% by weight of at least one unsaturated            nitrile,

    -   E) from 0 to 60% by weight of other additives,

    -   where the total of the percentages by weight of components A)        to E) is 100%.

The invention further relates to the use of the inventive moldingcompositions for production of fibers, foils, or moldings of any type,and to the moldings thus obtainable.

Polycarbonates are usually obtained from the reaction of alcohols withphosgene, or from the transesterification of alcohols or phenols withdialkyl or diaryl carbonates. Industrial importance is attached toaromatic polycarbonates, which are prepared from bisphenols, forexample, while the part played by aliphatic polycarbonates has hithertobeen subordinate in terms of market volume. In this connection, see alsoBecker/Braun, Kunststoff-Handbuch [Plastics Handbook], vol. 3/1,Polycarbonate, Polyacetale, Polyester, Celluloseester [Polycarbonates,polyacetals, polyesters, cellulose esters], Carl-Hanser-Verlag, Munich1992, pp. 118-119.

The structure of the aliphatic polycarbonates described is generallylinear or else has a small degree of branching. For example, U.S. Pat.No. 3,305,605 describes the use of solid linear polycarbonates with amolecular weight above 15 000 daltons as plasticizers for polyvinylpolymers.

To improve flowability, low-molecular-weight additives are usually addedto thermoplastics. However, the action of these additives is subject tosevere restriction, because, for example, the fall-off in mechanicalproperties becomes unacceptable when the amount added of the additiveincreases.

Highly functional polycarbonates of defined structure have beendisclosed only recently.

S. P. Rannard and N. J. Davis, J. Am. Chem. Soc. 2000, 122, 11729,describe the preparation of dendrimeric polycarbonates with perfectbranching, via reaction of carbonylbisimidazole as phosgene analog withbishydroxyethylamino-2-propanol. Syntheses giving perfect dendrimers aremultistage syntheses and therefore expensive, and not very suitable forconversion to industrial scale.

D. H. Bolton and K. L. Wooley, Macromolecules 1997, 30, 1890, describethe preparation of high-molecular-weight, very rigid hyperbranchedaromatic polycarbonates via reaction of1,1,1-tris(4′-hydroxyphenyl)ethane with carbonylbisimidazole.

Hyperbranched polycarbonates can also be prepared according to WO98/50453. In the process described in that specification, triols areagain reacted with carbonylbisimidazole. Initially imidazolides areproduced, and these then undergo a further intermolecular reaction togive the polycarbonates. In the method mentioned, the polycarbonates areproduced in the form of colorless or pale yellow rubber-like products.

The syntheses mentioned giving highly branched or hyperbranchedpolycarbonates have the following disadvantages:

-   -   a) the hyperbranched products are either high-melting or else        rubber-like, and this markedly restricts subsequent        processibility.    -   b) imidazole liberated during the reaction has to be removed        from the reaction mixture by a complicated process.    -   c) the reaction products always comprise terminal imidazolide        groups. These groups are labile and have to be converted by way        of a subsequent step into hydroxy groups, for example.    -   d) carbonyldiimidazole is a comparatively expensive chemical        which greatly increases raw material costs.

Low-molecular-weight additives are usually added to semicrystallinethermoplastics in order to improve flowability. However, the action ofthese additives is very restricted because, for example, the fall-off inmechanical properties becomes intolerable when more than a certainamount of the additive is added.

WO-97/45474 discloses thermoplastic compositions which comprisedendrimeric polyesters in the form of an AB₂ molecule in a polyester.Here, a polyhydric alcohol as core molecule reacts withdimethylpropionic acid as AB₂ molecule to give a dendrimeric polyester.This contains only OH functionalities at the end of the chain.Disadvantages of these mixtures are the high glass transitiontemperature of the dendrimeric polyesters, the comparatively complicatedpreparation process, and especially the poor solubility of thedendrimers in the polyester matrix.

According to the teaching of DE-A 101 32 928, the incorporation ofbranching agents of this type by means of compounding and solid-phasepost-condensation improves mechanical properties (molecular weightincrease). Disadvantages of the process variant described are the longpreparation time and the disadvantageous properties previouslymentioned.

DE 102004 005652.8 and DE 102004 005657.9 have previously proposed novelflow improvers for polyesters.

An object on which the present invention is based is therefore toprovide thermoplastic polyester molding compositions which have goodflowability together with good mechanical properties.

Accordingly, the molding compositions defined at the outset have beenfound. Preferred embodiments are given in the subclaims.

The inventive molding compositions comprise, as component (A), from 10to 98.99% by weight, preferably from 30 to 97.99% by weight, and inparticular from 30 to 95% by weight, of at least one thermoplasticpolyester other than B).

Use is generally made of polyesters A) based on aromatic dicarboxylicacids and on an aliphatic or aromatic dihydroxy compound.

A first group of preferred polyesters is that of polyalkyleneterephthalates, in particular those having from 2 to 10 carbon atoms inthe alcohol moiety.

Polyalkylene terephthalates of this type are known per se and aredescribed in the literature. Their main chain comprises an aromatic ringwhich derives from the aromatic dicarboxylic acid. There may also besubstitution in the aromatic ring, e.g. by halogen, such as chlorine orbromine, or by C₁-C₄-alkyl, such as methyl, ethyl, iso- or n-propyl, orn-, iso- or tert-butyl.

These polyalkylene terephthalates may be prepared by reacting aromaticdicarboxylic acids, or their esters or other ester-forming derivatives,with aliphatic dihydroxy compounds in a manner known per se.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid,terephthalic acid and isophthalic acid, and mixtures of these. Up to 30mol %, preferably not more than 10 mol %, of the aromatic dicarboxylicacids may be replaced by aliphatic or cycloaliphatic dicarboxylic acids,such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids andcyclohexanedicarboxylic acids.

Preferred aliphatic dihydroxy compounds are diols having from 2 to 6carbon atoms, in particular 1,2-ethanediol, 1,3-propanediol,1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol,1,4-cyclohexanedimethanol and neopentyl glycol, and mixtures of these.

Particularly preferred polyesters (A) are polyalkylene terephthalatesderived from alkanediols having from 2 to 6 carbon atoms. Among these,particular preference is given to polyethylene terephthalate,polypropylene terephthalate and polybutylene terephthalate, and mixturesof these. Preference is also given to PET and/or PBT which comprise, asother monomer units, up to 1% by weight, preferably up to 0.75% byweight, of 1,6-hexanediol and/or 2-methyl-1,5-pentanediol.

The viscosity number of the polyesters (A) is generally in the rangefrom 50 to 220, preferably from 80 to 160 measured in 0.5% strength byweight solution in a phenol/o-dichlorobenzene mixture (in a weight ratioof 1:1) at 25° C in accordance with ISO 1628.

Particular preference is given to polyesters whose carboxyl end groupcontent is up to 100 mval/kg of polyester, preferably up to 50 mval/kgof polyester and in particular up to 40 mval/kg of polyester. Polyestersof this type may be prepared, for example, by the process of DE-A 44 01055. The carboxyl end group content is usually determined by titrationmethods (e.g. potentiometry).

Particularly preferred molding compositions comprise, as component A), amixture of polyesters other than PBT, for example polyethyleneterephthalate (PET). The proportion of the polyethylene terephthalate,for example, in the mixture is preferably up to 50% by weight, inparticular from 10 to 35% by weight, based on 100% by weight of A).

It is also advantageous to use recycled PET materials (also termed scrapPET), if appropriate mixed with polyalkylene terephthalates, such asPBT.

Recycled materials are generally:

-   -   1) those known as post-industrial recycled materials: these are        production wastes during polycondensation or during processing,        e.g. sprues from injection molding, start-up material from        injection molding or extrusion, or edge trims from extruded        sheets or films.    -   2) post-consumer recycled materials: these are plastic items        which are collected and treated after utilization by the end        consumer. Blow-molded PET bottles for mineral water, soft drinks        and juices are easily the predominant items in terms of        quantity.

Both types of recycled material may be used either as ground material orin the form of pellets. In the latter case, the crude recycled materialsare separated and purified and then melted and pelletized using anextruder. This usually facilitates handling and free flow, and meteringfor further steps in processing.

The recycled materials used may either be pelletized or in the form ofregrind. The edge length should not be more than 10 mm, preferably lessthan 8 mm.

Because polyesters undergo hydrolytic cleavage during processing (due totraces of moisture) it is advisable to predry the recycled material. Theresidual moisture content after drying is preferably <0.2%, inparticular <0.05%.

Another group to be mentioned is that of fully aromatic polyestersderiving from aromatic dicarboxylic acids and aromatic dihydroxycompounds.

Suitable aromatic dicarboxylic acids are the compounds previouslydescribed for the polyalkylene terephthalates. The mixtures preferablyused are composed of from 5 to 100 mol % of isophthalic acid and from 0to 95 mol % of terephthalic acid, in particular from about 80% ofterephthalic acid with 20% of isophthalic acid up to approximatelyequivalent mixtures of these two acids.

The aromatic dihydroxy compounds preferably have the formula

where Z is an alkylene or cycloalkylene group having up to 8 carbonatoms, an arylene group having up to 12 carbon atoms, a carbonyl group,a sulfonyl group, oxygen or sulfur, or a chemical bond, and m is from 0to 2. The phenylene groups of the compounds may also have substitutionby C₁-C₆-alkyl or alkoxy and fluorine, chlorine or bromine.

Examples of parent compounds for these compounds are

-   dihydroxybiphenyl,-   di(hydroxyphenyl)alkane,-   di(hydroxyphenyl)cycloalkane,-   di(hydroxyphenyl)sulfide,-   di(hydroxyphenyl)ether,-   di(hydroxyphenyl)ketone,-   di(hydroxyphenyl)sulfoxide,-   α,α′-di(hydroxyphenyl)dialkylbenzene,-   di(hydroxyphenyl)sulfone, di(hydroxybenzoyl)benzene,-   resorcinol, and-   hydroquinone, and also the ring-alkylated and ring-halogenated    derivatives of these.

Among these, preference is given to

-   4,4′-dihydroxybiphenyl,-   2,4-di(4′-hydroxyphenyl)-2-methylbutane,-   α,α′-di(4-hydroxyphenyl)-p-diisopropylbenzene,-   2,2-di(3′-methyl-4′-hydroxyphenyl)propane, and-   2,2-di(3′-chloro-4′-hydroxyphenyl)propane,    and in particular to-   2,2-di(4′-hydroxyphenyl)propane-   2,2-di(3′,5-dichlorodihydroxyphenyl)propane,-   1,1-di(4′-hydroxyphenyl)cyclohexane,-   3,4′-dihydroxybenzophenone,-   4,4′-dihydroxydiphenyl sulfone and-   2,2-di(3′,5′-dimethyl-4′-hydroxyphenyl)propane    and mixtures of these.

It is, of course, also possible to use mixtures of polyalkyleneterephthalates and fully aromatic polyesters. These generally comprisefrom 20 to 98% by weight of the polyalkylene terephthalate and from 2 to80% by weight of the fully aromatic polyester.

It is, of course, also possible to use polyester block copolymers, suchas copolyetheresters. Products of this type are known per se and aredescribed in the literature, e.g. in U.S. Pat. No. 3,651,014.Corresponding products are also available commercially, e.g. Hytrel®(DuPont).

According to the invention, polyesters include halogen-freepolycarbonates. Examples of suitable halogen-free polycarbonates arethose based on diphenols of the formula

where Q is a single bond, a C₁-Q₈-alkylene group, a C₂-C₃-alkylidenegroup, a C₃-C₆-cycloalkylidene group, a C₆-C₁₂-arylene group, or —O—,—S— or —SO₂—, and m is a whole number from 0 to 2.

The phenylene radicals of the diphenols may also have substituents, suchas C₁-C₆-alkyl or C₁-C₆-alkoxy.

Examples of preferred diphenols of the formula are hydroquinone,resorcinol, 4,4′-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane,2,4-bis(4-hydroxyphenyl)-2-methylbutane and1,1-bis(4-hydroxyphenyl)cyclohexane. Particular preference is given to2,2-bis(4-hydroxyphenyl)propane and 1,1-bis(4-hydroxyphenyl)cyclohexane,and also to 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

Either homopolycarbonates or copolycarbonates are suitable as componentA, and preference is given to the copolycarbonates of bisphenol A, aswell as to bisphenol A homopolymer.

Suitable polycarbonates may be branched in a known manner, specificallyand preferably by incorporating 0.05 to 2.0 mol %, based on the total ofthe biphenols used, of at least trifunctional compounds, for examplethose having three or more phenolic OH groups.

Polycarbonates which have proven particularly suitable have relativeviscosities η_(ref) of from 1.10 to 1.50, in particular from 1.25 to1.40. This corresponds to an average molar mass M_(w) (weight-average)of from 10 000 to 200 000 g/mol, preferably from 20 000 to 80 000 g/mol.

The diphenols of the general formula are known per se or can be preparedby known processes.

The polycarbonates may, for example, be prepared by reacting thediphenols with phosgene in the interfacial process, or with phosgene inthe homogeneous-phase process (known as the pyridine process), and ineach case the desired molecular weight may be achieved in a known mannerby using an appropriate amount of known chain terminators. (In relationto polydiorganosiloxane-containing polycarbonates see, for example, DE-A33 34 782).

Examples of suitable chain terminators are phenol, p-tert-butylphenol,or else long-chain alkylphenols, such as 4-(1,3-tetramethylbutyl)phenolas in DE-A 28 42 005, or monoalkylphenols, or dialkylphenols with atotal of from 8 to 20 carbon atoms in the alkyl substituents as inDE-A-35 06 472, such as p-nonylphenol, 3,5-di-tert-butylphenol,p-tert-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)phenol and4-(3,5-dimethylheptyl)phenol.

For the purposes of the present invention, halogen-free polycarbonatesare polycarbonates composed of halogen-free biphenols, halogen-freechain terminators and, if appropriate, halogen-free branching agents,where the content of subordinate amounts at the ppm level ofhydrolyzable chlorine, resulting, for example, from the preparation ofthe polycarbonates with phosgene in the interfacial process, is notregarded as meriting the term halogen-containing for the purposes of theinvention. Polycarbonates of this type with contents of hydrolyzablechlorine at the ppm level are halogen-free polycarbonates for thepurposes of the present invention.

Other suitable components A) which may be mentioned are amorphouspolyester carbonates, where during the preparation process phosgene hasbeen replaced by aromatic dicarboxylic acid units, such as isophthalicacid and/or terephthalic acid units. Reference may be made at this pointto EP-A 711 810 for further details.

EP-A 365 916 describes other suitable copolycarbonates having cycloalkylradicals as monomer units.

It is also possible for bisphenol A to be replaced by bisphenol TMC.Polycarbonates of this type are obtainable from Bayer with the trademarkAPEC HT®.

As component B), the inventive molding compositions comprise from 0.01to 50% by weight, preferably from 0.5 to 20% by weight, and inparticular from 0.7 to 10% by weight, of a mixture composed of B1) atleast one highly branched or hyperbranched polycarbonate having an OHnumber of from 1 to 600 mg KOH/g of polycarbonate, preferably from 10 to550 mg KOH/g of polycarbonate, and in particular from 50 to 550 mg KOH/gof polycarbonate (to DIN 53240, Part 2), and of at least onehyperbranched polyester as component B2), or a mixture thereof, asexplained below.

For the purposes of this invention, hyperbranched polycarbonates B1) arenon-crosslinked macromolecules having hydroxy groups and carbonategroups, these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.

“Dendrimer” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”, thedefinition being

${DB} = {\frac{T + Z}{T + Z + L} \times 100\;\%}$(where T is the average number of terminal monomer units, Z is theaverage number of branched monomer units, and L is the average number oflinear monomer units in the macromolecules of the respectivesubstances).

Component B1) preferably has a number-average molar mass M_(n) of from100 to 15 000 g/mol, preferably from 200 to 12 000 g/mol, and inparticular from 500 to 10 000 g/mol (GPC, PMMA standard).

The glass transition temperature Tg is in particular from −80° C. to+140° C., preferably from −60 to 120° C. (according to DSC, DIN 53765).

In particular, the viscosity (mPas) at 23° C. (to DIN 53019) is from 50to 200 000, in particular from 100 to 150 000, and very particularlypreferably from 200 to 100 000.

Component B1) is preferably obtainable via a process which comprises atleast the following steps:

-   -   a) reacting at least one organic carbonate (A) of the general        formula RO[(CO)]_(n)OR with at least one aliphatic,        aliphatic/aromatic or aromatic alcohol (B) which has at least 3        OH groups, with elimination of alcohols ROH to give one or more        condensates (K), where each R, independently of the others, is a        straight-chain or branched aliphatic, aromatic/aliphatic, or        aromatic hydrocarbon radical having from 1 to 20 carbon atoms,        and where the radicals R may also have bonded to one another to        form a ring, and n is a whole number from 1 to 5, or    -   ab) reacting phosgene, diphosgene, or triphosgene with        abovementioned alcohol (B) with elimination of hydrogen        chloride, and    -   b) intermolecular reaction of the condensates (K) to give a        highly functional, highly branched, or highly functional,        hyperbranched polycarbonate,        where the quantitative proportion of the OH groups to the        carbonates in the reaction mixture is selected in such a way        that the condensates (K) have an average of either one carbonate        group and more than one OH group or one OH group and more than        one carbonate group.

The starting material used can comprise phosgene, diphosgene, ortriphosgene, but organic carbonates are preferred here.

Each of the radicals R of the organic carbonates (A) used as startingmaterial and having the general formula RO(CO)_(n)OR is, independentlyof the others, a straight-chain or branched aliphatic,aromatic/aliphatic, or aromatic hydrocarbon radical having from 1 to 20carbon atoms. The two radicals R may also have bonding to one another toform a ring. The radical is preferably an aliphatic hydrocarbon radical,and particularly preferably a straight-chain or branched alkyl radicalhaving from 1 to 5 carbon atoms, or a substituted or unsubstitutedphenyl radical.

In particular, simple carbonates of the formula RO(CO)_(n)OR are used; nis preferably from 1 to 3, in particular 1.

By way of example, dialkyl or diaryl carbonates may be prepared from thereaction of aliphatic, araliphatic, or aromatic alcohols, preferablymonoalcohols, with phosgene. They may also be prepared by way ofoxidative carbonylation of the alcohols or phenols by means of CO in thepresence of noble metals, oxygen, or NO_(x). In relation to preparationmethods for diaryl or dialkyl carbonates, see also “Ullmann'sEncyclopedia of Industrial Chemistry”, 6th edition, 2000 ElectronicRelease, Verlag Wiley-VCH.

Examples of suitable carbonates comprise aliphatic, aromatic/aliphaticor aromatic carbonates, such as ethylene carbonate, propylene 1,2- or1,3-carbonate, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate,dinaphthyl carbonate, ethyl phenyl carbonate, dibenzyl carbonate,dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutylcarbonate, diisobutyl carbonate, dipentyl carbonate, dihexyl carbonate,dicyclohexyl carbonate, diheptyl carbonate, dioctyl carbonate, didecylcarbonate, or didodecyl carbonate.

Examples of carbonates in which n is greater than 1 comprise dialkyldicarbonates, such as di(tert-butyl) dicarbonate, or dialkyltricarbonates, such as di(tert-butyl) tricarbonate.

It is preferable to use aliphatic carbonates, in particular those inwhich the radicals comprise from 1 to 5 carbon atoms, e.g. dimethylcarbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ordiisobutyl carbonate.

The organic carbonates are reacted with at least one aliphatic alcohol(B) which has at least 3 OH groups, or with mixtures of two or moredifferent alcohols.

Examples of compounds having at least three OH groups comprise glycerol,trimethylolmethane, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, tris(hydroxymethyl)amine, tris(hydroxyethyl)amine,tris(hydroxypropyl)amine, pentaerythritol, diglycerol, triglyerol,polyglycerols, bis(trimethylolpropane), tris(hydroxymethyl)isocyanurate, tris(hydroxyethyl) isocyanurate, phloroglucinol,trihydroxytoluene, trihydroxydimethylbenzene, phloroglucides,hexahydroxybenzene, 1,3,5-benzenetrimethanol,1,1,1-tris(4′-hydroxyphenyl)methane, 1,1,1-tris(4′-hydroxyphenyl)ethane,bis(trimethylolpropane), or sugars, e.g. glucose, trihydric or higherpolyhydric polyetherols based on trihydric or higher polyhydric alcoholsand ethylene oxide, propylene oxide, or butylene oxide, or polyesterols.Particular preference is given here to glycerol, trimethylolethane,trimethylolpropane, 1,2,4-butanetriol, pentaerythritol, and also theirpolyetherols based on ethylene oxide or propylene oxide.

These polyhydric alcohols may also be used in a mixture with dihydricalcohols (B′), with the proviso that the average total OH functionalityof all of the alcohols used is greater than 2. Examples of suitablecompounds having two OH groups comprise ethylene glycol, diethyleneglycol, triethylene glycol, 1,2- and 1,3-propanediol, dipropyleneglycol, tripropylene glycol, neopentyl glycol, 1,2-, 1,3-, and1,4-butanediol, 1,2-, 1,3-, and 1,5-pentanediol, hexanediol,cyclopentanediol, cyclohexanediol, cyclohexanedimethanol,bis(4-hydroxycyclohexyl)methane, bis(4-hydroxycyclohexyl)ethane,2,2-bis(4-hydroxycyclohexyl)propane,1,1′-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, resorcinol,hydroquinone, 4,4′-dihydroxyphenyl, bis(4-bis(hydroxyphenyl) sulfide,bis(4-hydroxyphenyl) sulfone, bis(hydroxymethyl)benzene,bis(hydroxymethyl)toluene, bis(p-hydroxyphenyl)methane,bis(p-hydroxyphenyl)ethane, 2,2-bis(p-hydroxyphenyl)propane,1,1-bis(p-hydroxy-phenyl)cyclohexane, dihydroxybenzophenone, dihydricpolyether polyols based on ethylene oxide, propylene oxide, butyleneoxide, or a mixture of these, polytetrahydrofuran, polycaprolactone, orpolyesterols based on diols and dicarboxylic acids.

The diols serve for fine adjustment of the properties of thepolycarbonate. If dihydric alcohols are used, the ratio of dihydricalcohols B′) to the at least trihydric alcohols (B) is set by the personskilled in the art as a function of the desired properties of thepolycarbonate. The amount of the alcohol(s) (B′) is generally from 0 to50 mol %, based on the total amount of all of the alcohols (B) and (B′).The amount is preferably from 0 to 45 mol %, particularly preferablyfrom 0 to 35 mol %, and very particularly preferably from 0 to 30 mol %.

The reaction of phosgene, diphosgene, or triphosgene with the alcohol oralcohol mixture generally takes place with elimination of hydrogenchloride, and the reaction of the carbonates with the alcohol or alcoholmixture to give the inventive highly functional highly branchedpolycarbonate takes place with elimination of the monohydric alcohol orphenol from the carbonate molecule.

The highly functional highly branched polycarbonates formed by theinventive process have termination by hydroxy groups and/or by carbonategroups after the reaction, i.e. with no further modification. They havegood solubility in various solvents, e.g. in water, alcohols, such asmethanol, ethanol, butanol, alcohol/water mixtures, acetone, 2-butanone,ethyl acetate, butyl acetate, methoxypropyl acetate, methoxyethylacetate, tetrahydrofuran, dimethylformamide, dimethylacetamide,N-methylpyrrolidone, ethylene carbonate, or propylene carbonate.

For the purposes of this invention, a highly functional polycarbonate isa product which, besides the carbonate groups which form the polymerskeleton, further has at least three, preferably at least six, morepreferably at least ten, terminal or pendant functional groups. Thefunctional groups are carbonate groups and/or OH groups. There is inprinciple no upper restriction on the number of the terminal or pendantfunctional groups, but products having a very high number of functionalgroups can have undesired properties, such as high viscosity or poorsolubility. The highly functional polycarbonates of the presentinvention mostly have not more than 500 terminal or pendant functionalgroups, preferably not more than 100 terminal or pendant functionalgroups.

When preparing the highly functional polycarbonates B1), it is necessaryto adjust the ratio of the compounds comprising OH groups to phosgene orcarbonate in such a way that the simplest resultant condensate(hereinafter termed condensate (K)) comprises an average of either onecarbonate group or carbamoyl group and more than one OH group or one OHgroup and more than one carbonate group or carbamoyl group. The simpleststructure of the condensate (K) composed of a carbonate (A) and a di- orpolyalcohol (B) here results in the arrangement XY_(n) or Y_(n)X, whereX is a carbonate group, Y is a hydroxy group, and n is generally anumber from 1 to 6, preferably from 1 to 4, particularly preferably from1 to 3. The reactive group which is the single resultant group here isgenerally termed “focal group” below.

By way of example, if during the preparation of the simplest condensate(K) from a carbonate and a dihydric alcohol the reaction ratio is 1:1,the average result is a molecule of XY type, illustrated by the generalformula 1.

During the preparation of the condensate (K) from a carbonate and atrihydric alcohol with a reaction ratio of 1:1, the average result is amolecule of XY₂ type, illustrated by the general formula 2. A carbonategroup is focal group here.

During the preparation of the condensate (K) from a carbonate and atetrahydric alcohol, likewise with the reaction ratio 1:1, the averageresult is a molecule of XY₃ type, illustrated by the general formula 3.A carbonate group is focal group here.

R in the formulae 1-3 has the definition given at the outset, and R¹ isan aliphatic or aromatic radical.

The condensate (K) may, by way of example, also be prepared from acarbonate and a trihydric alcohol, as illustrated by the general formula4, the molar reaction ratio being 2:1. Here, the average result is amolecule of X₂Y type, an OH group being focal group here. In formula 4,R and R¹ are as defined in formulae 1-3.

If difunctional compounds, e.g. a dicarbonate or a diol, are also addedto the components, this extends the chains, as illustrated by way ofexample in the general formula 5. The average result is again a moleculeof XY₂ type, a carbonate group being focal group.

In formula 5, R² is an organic, preferably aliphatic radical, and R andR¹ are as defined above.

It is also possible to use two or more condensates (K) for thesynthesis. Use may be made here firstly of two or more alcohols or oftwo or more carbonates. Mixtures of various condensates of differentstructure can moreover be obtained via selection of the ratio of thealcohols used and of the carbonates or of the phosgenes. This may beexplained taking the example of the reaction of a carbonate with atrihydric alcohol. If the starting materials are introduced in a ratioof 1:1, as illustrated in (II), the result is an XY₂ molecule. If thestarting materials are introduced in a ratio of 2:1 as illustrated in(IV), the result is an X₂Y molecule. If the ratio is between 1:1 and 2:1the result is a mixture of XY₂ and X₂Y molecules.

According to the invention, the simple condensates (K) described by wayof example in the formulae 1-5 preferentially react intermolecularly toform highly functional polycondensates, hereinafter termedpolycondensates (P). The reaction to give the condensate (K) and to givethe polycondensate (P) usually takes place at a temperature of from 0 to250° C., preferably from 60 to 160° C., in bulk or in solution. Use maygenerally be made here of any of the solvents which are inert withrespect to the respective starting materials. Preference is given to useof organic solvents, e.g. decane, dodecane, benzene, toluene,chlorobenzene, xylene, dimethylformamide, dimethylacetamide, or solventnaphtha.

In one preferred embodiment, the condensation reaction is carried out inbulk. The phenol or the monohydric alcohol ROH liberated during thereaction can be removed by distillation from the reaction equilibrium toaccelerate the reaction, if appropriate at reduced pressure.

If removal by distillation is intended, it is generally advisable to usethose carbonates which liberate alcohols ROH with a boiling point below140° C. during the reaction.

Catalysts or catalyst mixtures may also be added to accelerate thereaction. Suitable catalysts are compounds which catalyze esterificationor transesterification reactions, e.g. alkali metal hydroxides, alkalimetal carbonates, alkali metal hydrogencarbonates, preferably of sodium,of potassium, or of cesium, tertiary amines, guanidines, ammoniumcompounds, phosphonium compounds, organoaluminum, organotin, organozinc,organotitanium, organozirconium, or organobismuth compounds, or elsewhat are known as double metal cyanide (DMC) catalysts, e.g. asdescribed in DE 10138216 or DE 10147712.

It is preferable to use potassium hydroxide, potassium carbonate,potassium hydrogencarbonate, diazabicyclooctane (DABCO),diazabicyclononene (DBN), diazabicycloundecene (DBU), imidazoles, suchas imidazole, 1-methylimidazole, or 1,2-dimethylimidazole, titaniumtetrabutoxide, titanium tetraisopropoxide, dibutyltin oxide, dibutyltindilaurate, stannous dioctoate, zirconium acetylacetonate, or mixturesthereof.

The amount of catalyst generally added is from 50 to 10 000 ppm byweight, preferably from 100 to 5000 ppm by weight, based on the amountof the alcohol mixture or alcohol used.

It is also possible to control the intermolecular polycondensationreaction via addition of the suitable catalyst or else via selection ofa suitable temperature. The average molecular weight of the polymer (P)may moreover be adjusted by way of the composition of the startingcomponents and by way of the residence time.

The condensates (K) and the polycondensates (P) prepared at an elevatedtemperature are usually stable at room temperature for a relatively longperiod.

The nature of the condensates (K) permits polycondensates (P) withdifferent structures to result from the condensation reaction, thesehaving branching but no crosslinking. Furthermore, in the ideal case,the polycondensates (P) have either one carbonate group as focal groupand more than two OH groups or else one OH group as focal group and morethan two carbonate groups. The number of the reactive groups here is theresult of the nature of the condensates (K) used and the degree ofpolycondensation.

By way of example, a condensate (K) according to the general formula 2can react via triple intermolecular condensation to give two differentpolycondensates (P), represented in the general formulae 6 and 7.

In formulae 6 and 7, R and R¹ are as defined above.

There are various ways of terminating the intermolecularpolycondensation reaction. By way of example, the temperature may belowered to a range where the reaction stops and the product (K) or thepolycondensate (P) is storage-stable.

It is also possible to deactivate the catalyst, for example in the caseof basic catalysts via addition of Lewis acids or proton acids.

In another embodiment, as soon as the intermolecular reaction of thecondensate (K) has produced a polycondensate (P) with the desired degreeof polycondensation, a product having groups reactive toward the focalgroup of (P) may be added to the product (P) to terminate the reaction.For example, in the case of a carbonate group as focal group, by way ofexample, a mono-, di-, or polyamine may be added. In the case of ahydroxy group as focal group, by way of example, a mono-, di-, orpolyisocyanate, or a compound comprising epoxy groups, or an acidderivative which reacts with OH groups, can be added to the product (P).

The inventive highly functional polycarbonates are mostly prepared inthe pressure range from 0.1 mbar to 20 bar, preferably at from 1 mbar to5 bar, in reactors or reaction cascades which are operated batchwise,semicontinuously, or continuously.

The inventive products can be further processed without furtherpurification after their preparation by virtue of the abovementionedadjustment of the reaction conditions and, if appropriate, by virtue ofthe selection of the suitable solvent.

In another preferred embodiment, the product is stripped, i.e. freedfrom low-molecular-weight, volatile compounds. For this, once thedesired degree of conversion has been reached the catalyst mayoptionally be deactivated and the low-molecular-weight volatileconstituents, e.g. monoalcohols, phenols, carbonates, hydrogen chloride,or highly volatile oligomeric or cyclic compounds, can be removed bydistillation, if appropriate with introduction of a gas, preferablynitrogen, carbon dioxide or air, if appropriate at reduced pressure.

In another preferred embodiment, the inventive polycarbonates maycontain other functional groups besides the functional groups present atthis stage by virtue of the reaction. The functionalization may takeplace during the process to increase molecular weight, or elsesubsequently, i.e. after completion of the actual polycondensation.

If, prior to or during the process to increase molecular weight,components are added which have other functional groups or functionalelements besides hydroxy or carbonate groups, the result is apolycarbonate polymer with randomly distributed functionalities otherthan the carbonate or hydroxy groups.

Effects of this type can, by way of example, be achieved via addition,during the polycondensation, of compounds which bear other functionalgroups or functional elements, such as mercapto groups, primary,secondary or tertiary amino groups, ether groups, derivatives ofcarboxylic acids, derivatives of sulfonic acids, derivatives ofphosphonic acids, silane groups, siloxane groups, aryl radicals, orlong-chain alkyl radicals, besides hydroxy groups, carbonate groups orcarbamoyl groups. Examples of compounds which may be used formodification by means of carbamate groups are ethanolamine,propanolamine, isopropanolamine, 2-(butylamino)ethanol,2-(cyclo-hexylamino)ethanol, 2-amino-1-butanol,2-(2′-aminoethoxy)ethanol or higher alkoxylation products of ammonia,4-hydroxypiperidine, 1-hydroxyethylpiperazine, diethanolamine,dipropanolamine, diisopropanolamine, tris(hydroxymethyl)amino-methane,tris(hydroxyethyl)aminomethane, ethylenediamine, propylenediamine,hexamethylenediamine or isophoronediamine.

An example of a compound which can be used for modification withmercapto groups is mercaptoethanol. By way of example, tertiary aminogroups can be produced via incorporation of N-methyldiethanolamine,N-methyldipropanolamine or N,N-dimethylethanolamine. By way of example,ether groups may be generated via co-condensation of dihydric or higherpolyhydric polyetherols. Long-chain alkyl radicals can be introduced viareaction with long-chain alkanediols, and reaction with alkyl or aryldiisocyanates generates polycarbonates having alkyl, aryl, and urethanegroups or urea groups.

Ester groups can be produced via addition of dicarboxylic acids ortricarboxylic acids, for example, dimethyl terephthalate, ortricarboxylic esters.

Subsequent functionalization can be achieved by using an additional stepof the process (step c)) to react the resultant highly functional highlybranched, or highly functional hyperbranched polycarbonate with asuitable functionalizing reagent which can react with the OH and/orcarbonate groups or carbamoyl groups of the polycarbonate.

By way of example, highly functional highly branched, or highlyfunctional hyperbranched polycarbonates containing hydroxy groups can bemodified via addition of molecules containing acid groups or containingisocyanate groups. By way of example, polycarbonates containing acidgroups can be obtained via reaction with compounds containing anhydridegroups.

Highly functional polycarbonates comprising hydroxy groups may moreoveralso be converted into highly functional polycarbonate polyether polyolsvia reaction with alkylene oxides, e.g. ethylene oxide, propylene oxide,or butylene oxide.

A great advantage of the process is its cost-effectiveness. Both thereaction to give a condensate (K) or polycondensate (P) and also thereaction of (K) or (P) to give polycarbonates with other functionalgroups or elements can take place in one reactor, this beingadvantageous technically and in terms of cost-effectiveness.

The inventive molding compositions may comprise, as component B2), atleast one hyperbranched polyester of A_(x)B_(y) type, where

x is at least 1.1, preferably at least 1.3, in particular at least 2

y is at least 2.1, preferably at least 2.5, in particular at least 3.

Use may also be made of mixtures as units A and/or B, of course.

An A_(x)B_(y)-type polyester is a condensate composed of an x-functionalmolecule A and a y-functional molecule B. By way of example, mention maybe made of a polyester composed of adipic acid as molecule A (x=2) andglycerol as molecule B (y=3).

For the purposes of this invention, hyperbranched polyesters B2) arenon-crosslinked macromolecules having hydroxy groups and carboxy groups,these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no.14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.

“Dendrimer” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”.

Component B2) preferably has an M_(n) of from 300 to 30 000 g/mol, inparticular from 400 to 25 000 g/mol, and very particularly from 500 to20 000 g/mol, determined by means of GPC, PMMA standard,dimethylacetamide eluent.

B2) preferably has an OH number of from 0 to 600 mg KOH/g of polyester,preferably of from 1 to 500 mg KOH/g of polyester, in particular from 20to 500 mg KOH/g of polyester to DIN 53240, and preferably a COOH numberof from 0 to 600 mg KOH/g of polyester, preferably from 1 to 500 mgKOH/g of polyester, and in particular from 2 to 500 mg KOH/g ofpolyester.

The T_(g) is preferably from −50° C. to 140° C., and in particular from−50 to 100° C. (by means of DSC, to DIN 53765).

Preference is particularly given to those components B2) in which atleast one OH or COOH number is greater than 0, preferably greater than0.1, and in particular greater than 0.5.

The inventive component B2) is in particular obtainable via theprocesses described below, specifically by reacting

-   -   (a) one or more dicarboxylic acids, or one or more derivatives        of the same, with one or more at least trihydric alcohols, or    -   (b) one or more tricarboxylic acids or higher polycarboxylic        acids, or one or more derivatives of the same, with one or more        diols

in the presence of a solvent and optionally in the presence of aninorganic, organometallic, or low-molecular-weight organic catalyst, orof an enzyme. The reaction in solvent is the preferred preparationmethod.

For the purposes of the present invention, highly functionalhyperbranched polyesters B2) have molecular and structuralnon-uniformity. Their molecular non-uniformity distinguishes them fromdendrimers, and they can therefore be prepared at considerably lowercost.

Among the dicarboxylic acids which can be reacted according to variant(a) are, by way of example, oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, undecane-α,ω-dicarboxylic acid, dodecane-α,ω-dicarboxylicacid, cis- and trans-cyclohexane-1,2-dicarboxylic acid, cis- andtrans-cyclohexane-1,3-dicarboxylic acid, cis- andtrans-cyclohexane-1,4-dicarboxylic acid, cis- andtrans-cyclopentane-1,2-dicarboxylic acid, and cis- andtrans-cyclopentane-1,3-dicarboxylic acid,

and the abovementioned dicarboxylic acids may have substitution by oneor more radicals selected from

C₁-C₁₀-alkyl groups, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl, n-nonyl, andn-decyl,

C₃-C₁₂-cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl, and cyclododecyl; preference is given to cyclopentyl,cyclohexyl, and cycloheptyl;

alkylene groups, such as methylene or ethylidene, or

C₆-C₁₄-aryl groups, such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl, and 9-phenanthryl, preferably phenyl, 1-naphthyl, and2-naphthyl, particularly preferably phenyl.

Examples which may be mentioned of representatives of substituteddicarboxylic acids are: 2-methylmalonic acid, 2-ethylmalonic acid,2-phenylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid,2-phenylsuccinic acid, itaconic acid, 3,3-dimethylglutaric acid.

Among the dicarboxylic acids which can be reacted according to variant(a) are also ethylenically unsaturated acids, such as maleic acid andfumaric acid, and aromatic dicarboxylic acids, such as phthalic acid,isophthalic acid or terephthalic acid.

It is also possible to use mixtures of two or more of the abovementionedrepresentative compounds.

The dicarboxylic acids may either be used as they stand or be used inthe form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono- or dialkyl esters, preferably mono- or dimethyl esters, or        the corresponding mono- or diethyl esters, or else the mono- and        dialkyl esters derived from higher alcohols, such as n-propanol,        isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol,        n-hexanol,    -   and also mono- and divinyl esters, and    -   mixed esters, preferably methyl ethyl esters.

In the preferred preparation process it is also possible to use amixture composed of a dicarboxylic acid and one or more of itsderivatives. Equally, it is possible to use a mixture of two or moredifferent derivatives of one or more dicarboxylic acids.

It is particularly preferable to use succinic acid, glutaric acid,adipic acid, phthalic acid, isophthalic acid, terephthalic acid, or themono- or dimethyl ester thereof. It is very particularly preferable touse adipic acid.

Examples of at least trihydric alcohols which may be reacted are:glycerol, butane-1,2,4-triol, n-pentane-1,2,5-triol,n-pentane-1,3,5-triol, n-hexane-1,2,6-triol, n-hexane-1,2,5-triol,n-hexane-1,3,6-triol, trimethylolbutane, trimethylolpropane orditrimethylolpropane, trimethylolethane, pentaerythritol ordipentaerythritol; sugar alcohols, such as mesoerythritol, threitol,sorbitol, mannitol, or mixtures of the above at least trihydricalcohols. It is preferable to use glycerol, trimethylolpropane,trimethylolethane, and pentaerythritol.

Examples of tricarboxylic acids or polycarboxylic acids which can bereacted according to variant (b) are benzene-1,2,4-tricarboxylic acid,benzene-1,3,5-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid,and mellitic acid.

Tricarboxylic acids or polycarboxylic acids may be used in the inventivereaction either as they stand or else in the form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono-, di-, or trialkyl esters, preferably mono-, di-, or        trimethyl esters, or the corresponding mono-, di-, or triethyl        esters, or else the mono-, di-, and triesters derived from        higher alcohols, such as n-propanol, isopropanol, n-butanol,        isobutanol, tert-butanol, n-pentanol, n-hexanol, or else mono-,        di-, or trivinyl esters    -   and mixed methyl ethyl esters.

For the purposes of the present invention, it is also possible to use amixture composed of a tri- or polycarboxylic acid and one or more of itsderivatives. For the purposes of the present invention it is likewisepossible to use a mixture of two or more different derivatives of one ormore tri- or polycarboxylic acids, in order to obtain component B2).

Examples of diols used for variant (b) of the present invention areethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,2-diol,butane-1,3-diol, butane-1,4-diol, butane-2,3-diol, pentane-1,2-diol,pentane-1,3-diol, pentane-1,4-diol, pentane-1,5-diol, pentane-2,3-diol,pentane-2,4-diol, hexane-1,2-diol, hexane-1,3-diol, hexane-1,4-diol,hexane-1,5-diol, hexane-1,6-diol, hexane-2,5-diol, heptane-1,2-diol,1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol,1,10-decanediol, 1,2-decanediol, 1,12-dodecanediol, 1,2-dodecanediol,1,5-hexadiene-3,4-diol, cyclopentanediols, cyclohexanediols, inositoland derivatives, (2)-methylpentane-2,4-diol,2,4-dimethyl-pentane-2,4-diol, 2-ethylhexane-1,3-diol,2,5-dimethylhexane-2,5-diol, 2,2,4-trimethyl-pentane-1,3-diol, pinacol,diethylene glycol, triethylene glycol, dipropylene glycol, tripropyleneglycol, polyethylene glycols HO(CH₂CH₂O)_(n)—H or polypropylene glycolsHO(CH[CH₃]CH₂O)_(n)—H or mixtures of two or more representativecompounds of the above compounds, where n is a whole number and n=4 to25. One, or else both, of the hydroxy groups here in the abovementioneddiols may also be replaced by SH groups. Preference is given to ethyleneglycol, propane-1,2-diol, and diethylene glycol, triethylene glycol,dipropylene glycol, and tripropylene glycol.

The molar ratio of the molecules A to molecules B in the A_(x)B_(y)polyester in the variants (a) and (b) is from 4:1 to 1:4, in particularfrom 2:1 to 1:2.

The at least trihydric alcohols reacted according to variant (a) of theprocess may have hydroxy groups of which all have identical reactivity.Preference is also given here to at least trihydric alcohols whose OHgroups initially have identical reactivity, but where reaction with atleast one acid group can induce a fall-off in reactivity of theremaining OH groups as a result of steric or electronic effects. By wayof example, this applies when trimethylolpropane or pentaerythritol isused.

However, the at least trihydric alcohols reacted according to variant(a) may also have hydroxy groups having at least two different chemicalreactivities.

The different reactivity of the functional groups here may either derivefrom chemical causes (e.g. primary/secondary/tertiary OH group) or fromsteric causes.

By way of example, the triol may comprise a triol which has primary andsecondary hydroxy groups, preferred example being glycerol.

When the inventive reaction is carried out according to variant (a), itis preferable to operate in the absence of diols and monohydricalcohols.

When the inventive reaction is carried out according to variant (b), itis preferable to operate in the absence of mono- or dicarboxylic acids.

The inventive process is carried out in the presence of a solvent.Examples of suitable compounds are hydrocarbons, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene and ortho- and meta-dichlorobenzene. Othervery particularly suitable solvents in the absence of acidic catalystsare: ethers, such as dioxane or tetrahydrofuran, and ketones, such asmethyl ethyl ketone and methyl isobutyl ketone.

According to the invention, the amount of solvent added is at least 0.1%by weight, based on the weight of the starting materials used and to bereacted, preferably at least 1% by weight, and particularly preferablyat least 10% by weight. It is also possible to use excesses of solvent,based on the weight of starting materials used and to be reacted, e.g.from 1.01 to 10 times the amount. Solvent amounts of more than 100 timesthe weight of the starting materials used and to be reacted are notadvantageous, because the reaction rate reduces markedly at markedlylower concentrations of the reactants, giving uneconomically longreaction times.

To carry out the process preferred according to the invention,operations may be carried out in the presence of a dehydrating agent asadditive, added at the start of the reaction. Suitable examples aremolecular sieves, in particular 4 Å molecular sieve, MgSO₄, and Na₂SO₄.During the reaction it is also possible to add further dehydrating agentor to replace dehydrating agent by fresh dehydrating agent. During thereaction it is also possible to remove the water or alcohol formed bydistillation and, for example, to use a water separator.

The process may be carried out in the absence of acidic catalysts. It ispreferable to operate in the presence of an acidic inorganic,organometallic, or organic catalyst, or a mixture composed of two ormore acidic inorganic, organometallic, or organic catalysts.

For the purposes of the present invention, examples of acidic inorganiccatalysts are sulfuric acid, phosphoric acid, phosphonic acid,hypophosphorous acid, aluminum sulfate hydrate, alum, acidic silica gel(pH=6, in particular=5), and acidic aluminum oxide. Examples of othercompounds which can be used as acidic inorganic catalysts are aluminumcompounds of the general formula Al(OR)₃ and titanates of the generalformula Ti(OR)₄, where each of the radicals R may be identical ordifferent and is selected independently of the others from

C₁-C₁₀-alkyl radicals, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl, n-nonyl, andn-decyl,

C₃-C₁₂-cycloalkyl radicals, such as cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl,cyclodecyl, cycloundecyl, and cyclododecyl; preference is given tocyclopentyl, cyclohexyl, and cycloheptyl.

Each of the radicals R in Al(OR)₃ or Ti(OR)₄ is preferably identical andselected from isopropyl or 2-ethylhexyl.

Examples of preferred acidic organometallic catalysts are selected fromdialkyltin oxides R₂SnO, where R is defined as above. A particularlypreferred representative compound for acidic organometallic catalysts isdi-n-butyltin oxide, which is commercially available as “oxo-tin”, ordi-n-butyltin dilaurate.

Preferred acidic organic catalysts are acidic organic compounds having,by way of example, phosphate groups, sulfonic acid groups, sulfategroups, or phosphonic acid groups. Particular preference is given tosulfonic acids, such as para-toluenesulfonic acid. Acidic ion exchangersmay also be used as acidic organic catalysts, e.g. polystyrene resinscontaining sulfonic acid groups and crosslinked with about 2 mol % ofdivinylbenzene.

It is also possible to use combinations of two or more of theabovementioned catalysts. It is also possible to use an immobilized formof those organic or organometallic, or else inorganic catalysts whichtake the form of discrete molecules.

If the intention is to use acidic inorganic, organometallic, or organiccatalysts, according to the invention the amount used is from 0.1 to 10%by weight, preferably from 0.2 to 2% by weight, of catalyst.

The inventive process is carried out under inert gas, e.g. under carbondioxide, nitrogen, or a noble gas, among which mention may particularlybe made of argon.

The inventive process is carried out at temperatures of from 60 to 200°C. It is preferable to operate at temperatures of from 130 to 180° C.,in particular up to 150° C., or below that temperature. Maximumtemperatures up to 145° C. are particularly preferred, and temperaturesup to 135° C. are very particularly preferred.

The pressure conditions for the inventive process are not critical perse. It is possible to operate at markedly reduced pressure, e.g. at from10 to 500 mbar. The inventive process may also be carried out atpressures above 500 mbar. A reaction at atmospheric pressure ispreferred for reasons of simplicity; however, conduct at slightlyincreased pressure is also possible, e.g. up to 1200 mbar. It is alsopossible to operate at markedly increased pressure, e.g. at pressures upto 10 bar. Reaction at atmospheric pressure is preferred.

The reaction time for the inventive process is usually from 10 minutesto 25 hours, preferably from 30 minutes to 10 hours, and particularlypreferably from one to 8 hours.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can easily be isolated, e.g. by removing the catalyst byfiltration and concentrating the mixture, the concentration process hereusually being carried out at reduced pressure. Other work-up methodswith good suitability are precipitation after addition of water,followed by washing and drying.

Component B2) can also be prepared in the presence of enzymes ordecomposition products of enzymes (according to DE-A 101 63163). For thepurposes of the present invention, the term acidic organic catalystsdoes not include the dicarboxylic acids reacted according to theinvention.

It is preferable to use lipases or esterases. Lipases and esterases withgood suitability are Candida cylindracea, Candida lipolytica, Candidarugosa, Candida antarctica, Candida utilis, Chromobacterium viscosum,Geolrichum viscosum, Geotrichum candidum, Mucor javanicus, Mucor mihei,pig pancreas, pseudomonas spp., pseudomonas fluorescens, Pseudomonascepacia, Rhizopus arrhizus, Rhizopus delemar, Rhizopus niveus, Rhizopusoryzae, Aspergillus niger, Penicillium roquefortii, Penicilliumcamembertii, or esterase from Bacillus spp. and Bacillusthermoglucosidasius. Candida antarctica lipase B is particularlypreferred. The enzymes listed are commercially available, for examplefrom Novozymes Biotech Inc., Denmark.

The enzyme is preferably used in immobilized form, for example on silicagel or Lewatit®. The processes for immobilizing enzymes are known perse, e.g. from Kurt Faber, “Biotransformations in organic chemistry”, 3rdedition 1997, Springer Verlag, Chapter 3.2 “Immobilization” pp. 345-356.Immobilized enzymes are commercially available, for example fromNovozymes Biotech Inc., Denmark.

The amount of immobilized enzyme used is from 0.1 to 20% by weight, inparticular from 10 to 15% by weight, based on the total weight of thestarting materials used and to be reacted.

The inventive process is carried out at temperatures above 60° C. It ispreferable to operate at temperatures of 100° C. or below thattemperature. Preference is given to temperatures up to 80° C., veryparticular preference is given to temperatures of from 62 to 75° C., andstill more preference is given to temperatures of from 65 to 75° C.

The inventive process is carried out in the presence of a solvent.Examples of suitable compounds are hydrocarbons, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene and ortho- and meta-dichlorobenzene. Othervery particularly suitable solvents are: ethers, such as dioxane ortetrahydrofuran, and ketones, such as methyl ethyl ketone and methylisobutyl ketone.

The amount of solvent added is at least 5 parts by weight, based on theweight of the starting materials used and to be reacted, preferably atleast 50 parts by weight, and particularly preferably at least 100 partsby weight. Amounts of more than 10 000 parts by weight of solvent areundesirable, because the reaction rate decreases markedly at markedlylower concentrations, giving uneconomically long reaction times.

The inventive process is carried out at pressures above 500 mbar.Preference is given to the reaction at atmospheric pressure or slightlyincreased pressure, for example at up to 1200 mbar. It is also possibleto operate under markedly increased pressure, for example at pressuresup to 10 bar. The reaction at atmospheric pressure is preferred.

The reaction time for the inventive process is usually from 4 hours to 6days, preferably from 5 hours to 5 days, and particularly preferablyfrom 8 hours to 4 days.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can be isolated, e.g. by removing the enzyme by filtrationand concentrating the mixture, the concentration process here usuallybeing carried out at reduced pressure. Other work-up methods with goodsuitability are precipitation after addition of water, followed bywashing and drying.

The highly functional, hyperbranched polyesters obtainable by theinventive process feature particularly low contents of discolored andresinified material. For the definition of hyperbranched polymers, seealso: P. J. Flory, J. Am. Chem. Soc. 1952, 74, 2718, and A. Sunder etal., Chem. Eur. J. 2000, 6, no. 1, 1-8. However, in the context of thepresent invention, “highly functional hyperbranched” means that thedegree of branching, i.e. the average number of dendritic linkages plusthe average number of end groups per molecule is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 30 to 90% (seein this connection H. Frey et al. Acta Polym. 1997, 48, 30).

The inventive polyesters have a molar mass M_(w) of from 500 to 50 000g/mol, preferably from 1000 to 20 000 g/mol, particularly preferablyfrom 1000 to 19 000 g/mol. The polydispersity is from 1.2 to 50,preferably from 1.4 to 40, particularly preferably from 1.5 to 30, andvery particularly preferably from 1.5 to 10. They are usually verysoluble, i.e. clear solutions can be prepared using up to 50% by weight,in some cases even up to 80% by weight, of the inventive polyesters intetrahydrofuran (THF), n-butyl acetate, ethanol, and numerous othersolvents, with no gel particles detectable by the naked eye.

The inventive highly functional hyperbranched polyesters arecarboxy-terminated, carboxy- and hydroxy-terminated, and preferablyhydroxy-terminated.

If a mixture of the components B1) and B2) is used, the ratios of thecomponents B1): B2) are preferably from 1:20 to 20:1, in particular from1:15 to 15:1, and very particularly from 1:5 to 5:1.

The hyperbranched polycarbonates B1)/polyesters B2) used take the formof particles of size from 20 to 500 nm. These nanoparticles are presentin fine dispersion in the polymer blend, and the size of the particlesin the compounded material is from 20 to 500 nm, preferably from 50 to300 nm.

Compounded materials of this type are commercially available asUltradur® high speed.

As component C) in the inventive molding compositions, use is made ofamounts of from 1 to 60% by weight, based on the entirety of componentsA to E, of a graft copolymer or of a mixture of different graftcopolymers. Preferred inventive molding compositions comprise from 2 to50% by weight, particularly preferably from 3 to 40% by weight, of atleast one graft copolymer C other than elastomeric polymers E).

The graft polymers C are composed of

-   -   c₁) from 20 to 80% by weight, preferably from 50 to 70% by        weight, of a graft base composed of an elastomeric polymer based        on alkyl acrylates having from 1 to 8 carbon atoms in the alkyl        moiety and having a glass transition temperature below 10° C.    -   c₂) from 20 to 80% by weight, preferably from 30 to 50% by        weight, of a graft composed of    -   c₂₁) from 60 to 95% by weight, preferably from 70 to 85% by        weight, of styrene or of substituted styrenes of the general        formula I

-   -   -   where R is a C₁-C₈-alkyl radical, preferably methyl or            ethyl, or hydrogen, and R¹ is a C₁-C₈-alkyl radical,            preferably methyl or ethyl, and n is 1, 2, or 3, or a            mixture of these, and

    -   C₂₂) from 5 to 40% by weight, preferably from 15 to 30% by        weight, of at least one unsaturated nitrile, preferably        acrylonitrile or methacrylonitrile, or a mixture of these.

Polymers which may be used for the graft base c, are those whose glasstransition temperature is below 10° C., preferably below 0° C.,particularly preferably below −20° C. Examples of these are elastomersbased on C₁-C₈-alkyl esters of acrylic acid, which, if appropriate, maycomprise other comonomers.

Preferred graft bases c, are those composed of

-   -   c₁₁) from 70 to 99.9% by weight, preferably from 99% by weight,        of at least one alkyl acrylate having from 1 to 8 carbon atoms        in the alkyl radical, preferably n-butyl acrylate and/or        2-ethylhexyl acrylate, in particular n-butyl acrylate as sole        alkyl acrylate    -   c₁₂) from 0 to 30% by weight, in particular from 20 to 30% by        weight, of another copolymerizable monoethylenically unsaturated        monomer, e.g. butadiene, isoprene, styrene, acrylonitrile,        methyl methacrylate, or vinyl methyl ether, or a mixture of        these,    -   c₁₃) from 0.1 to 5% by weight, preferably from 1 to 4% by        weight, of a copolymerizable, polyfunctional, preferably bi- or        trifunctional, monomer which brings about crosslinking.        -   Suitable bi- or polyfunctional crosslinking monomers c₁₃)            here are those which preferably comprise two, or if            appropriate three or more, ethylenic double bonds capable of            copolymerization and not conjugated in 1,3-positions.            Examples of suitable crosslinking monomers are            divinylbenzene, diallyl maleate, diallyl fumarate, diallyl            phthalate, triallyl cyanurate, or triallyl isocyanurate. The            acrylic ester of tricyclodecenyl alcohol has proven to be a            particularly advantageous crosslinking monomer (cf. DE-A 12            60 135).

This type of graft base is known per se and described in the literature,e.g. in DE-A 31 49 358.

Among the grafts c₂, preference is given to those in which c₂₁ isstyrene or α-methyl-styrene or a mixture of these, and in which c₂₂ isacrylonitrile or methacrylonitrile. Preferred monomer mixtures used areespecially styrene and acrylonitrile or α-methyl-styrene andacrylonitrile. The grafts are obtainable via copolymerization ofcomponents c₂₁ and c₂₂.

The graft base c₁ of the graft polymer C) is composed of the componentsc₁₁, if appropriate c₁₂, and c₁₃, and is also termed ASA rubber. Itspreparation is known per se and is described by way of example in DE-A28 26 925, DE-A 31 49 358, and DE-A3414 118.

The graft polymers C may be prepared by the method described in DE-C 1260 135, for example.

The construction of the graft (graft shell) of the graft polymers mayinvolve one or two stages.

In the case of single-stage construction of the graft shell, a mixtureof the monomers c₂₁ and c₂₂ in the desired ratio by weight in the rangefrom 95:5 to 50:50, preferably from 90:10 to 65:35, is polymerized inthe presence of the elastomer c₁, in a manner known per se (cf., forexample, DE-A 28 26 925), preferably in emulsion.

In the case of two-stage construction of the graft shell c₂, the 1ststage generally makes up from 20 to 70% by weight, preferably from 25 to50% by weight, based on c₂. Its preparation preferably uses only styreneor substituted styrenes, or a mixture of these (c₂₁).

The 2nd stage of the graft shell generally makes up from 30 to 80% byweight, in particular from 50 to 75% by weight, based in each case onc₂. Its preparation uses mixtures composed of the monomers c₂, and ofthe nitriles c₂₂, in a c₂₁/c₂₂ ratio by weight which is generally from90:10 to 60:40, in particular from 80:20 to 70:30.

The selection of the conditions for the graft polymerization process ispreferably such that the particle sizes obtained are from 50 to 700 nm(d₅₀ value from the cumulative weight distribution). Measures for thispurpose are known and are described by way of example in DE-A 2826925.

The seed latex process can be used directly to prepare a coarse-particlerubber dispersion.

In order to obtain products of maximum toughness, it is oftenadvantageous to use a mixture of at least two graft polymers withdifferent particle size.

To achieve this, the particles of the rubber are enlarged in a knownmanner, e.g. via agglomeration, thus giving the latex a bimodalcomposition (from 50 to 180 nm and from 200 to 700 nm).

One preferred embodiment uses a mixture composed of two graft polymerswith particle diameters (d₅₀ value from the cumulative weightdistribution) of from 50 to 180 nm and, respectively, from 200 to 700nm, in a ratio of from 70:30 to 30:70 by weight.

The chemical structure of the two graft polymers is preferablyidentical, but the shell of the coarse-particle graft polymer may inparticular also be constructed in two stages.

Mixtures composed of the components where the latter comprise a coarse-and fine-particle graft polymer are described by way of example in DE-A36 15 607. Mixtures composed of the components where the latter comprisea two-stage graft shell are known from EP-A 111 260.

As component D, the inventive molding compositions may comprise from 0to 60% by weight, based on the entirety of components A to E, of atleast one copolymer based on styrene or on substituted styrenes and onunsaturated nitriles. Preferred inventive molding compositions compriseproportions of from 1 to 45% by weight, in particular from 2 to 40% byweight, of component D, based on the entirety of components A to E.

According to the invention, the copolymers D are composed of

-   -   d₁) from 60 to 95% by weight, preferably from 70 to 85% by        weight, of styrene or of substituted styrenes of the general        formula I, or a mixture of these, and    -   d₂) from 5 to 40% by weight, preferably from 15 to 30% by        weight, of at least one unsaturated nitrile, preferably        acrylonitrile or methacrylonitrile or a mixture of these.

The copolymers D are resin-like, thermoplastic, and rubber-free.Particularly preferred copolymers D are those composed of styrene andacrylonitrile, of a-methylstyrene and acrylonitrile, or of styrene,c-methylstyrene, and acrylonitrile. It is also possible to makesimultaneous use of two or more of the copolymers described.

The copolymers D are known per se and may be prepared via free-radicalpolymerization, in particular via emulsion, suspension, solution, orbulk polymerization. They have viscosity numbers in the range from 40 to160, corresponding to average molecular weights M_(w) (weight-average)of from 40 000 to 2 000 000.

As component E), the inventive molding compositions may comprise from 0to 60% by weight, in particular up to 50% by weight, of additives andprocessing aids other than B).

As component E), the inventive molding compositions may comprise from 0to 5% by weight, preferably from 0.05 to 3% by weight, and in particularfrom 0.1 to 2% by weight, of at least one ester or amide of saturated orunsaturated aliphatic carboxylic acids having from 10 to 40, preferablyfrom 16 to 22, carbon atoms with saturated aliphatic alcohols or amineshaving from 2 to 40, preferably from 2 to 6, carbon atoms.

The carboxylic acids may be monobasic or dibasic. Examples which may bementioned are pelargonic acid, palmitic acid, lauric acid, margaricacid, dodecanedioic acid, behenic acid, and particularly preferablystearic acid, capric acid, and also montanic acid (a mixture of fattyacids having from 30 to 40 carbon atoms).

The aliphatic alcohols may be mono- to tetrahydric. Examples of alcoholsare n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propyleneglycol, neopentyl glycol, pentaerythritol, preference being given toglycerol and pentaerythritol.

The aliphatic amines may be mono-, di- or triamines. Examples of theseare stearylamine, ethylenediamine, propylenediamine,hexamethylenediamine, di(6-aminohexyl)amine, particular preference beinggiven to ethylenediamine and hexamethylenediamine. Correspondingly,preferred esters or amides are glycerol distearate, glyceroltristearate, ethylenediamine distearate, glycerol monopalmitate,glycerol trilaurate, glycerol monobehenate, and pentaerythrityltetrastearate.

It is also possible to use mixtures of various esters or amides, oresters with amides combined, the mixing ratio here being as desired.

Examples of amounts of other usual additives E) are up to 40% by weight,preferably up to 30% by weight, of elastomeric polymers (also oftentermed impact modifiers, elastomers, or rubbers) other than C).

These are very generally copolymers which have preferably been built upfrom at least two of the following monomers: ethylene, propylene,butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene,acrylonitrile and acrylates and/or methacrylates having from 1 to 18carbon atoms in the alcohol component.

Polymers of this type are described, for example, in Houben-Weyl,Methoden der organischen Chemie, Vol. 14/1 (Georg-Thieme-Verlag,Stuttgart, Germany, 1961), pages 392-406, and in the monograph by C. B.Bucknall, “Toughened Plastics” (Applied Science Publishers, London, UK,1977).

Fibrous or particulate fillers E) which may be mentioned are carbonfibers, glass fibers, glass beads, amorphous silica, asbestos, calciumsilicate, calcium metasilicate, magnesium carbonate, kaolin, chalk,powdered quartz, mica, barium sulfate, and feldspar, the amounts used ofthese being up to 50% by weight, in particular up to 40% by weight.

Preferred fibrous fillers which may be mentioned are carbon fibers,aramid fibers, and potassium titanate fibers, particular preferencebeing given to glass fibers in the form of E glass. The forms used ofthese may be the commercially available forms of chopped glass orrovings.

Particular preference is given to mixtures of glass fibers E) withcomponent B) in a ratio of from 1:100 to 1:2, preferably from 1:10 to1:3.

The fibrous fillers may have been surface-pretreated with a silanecompound to improve compatibility with the thermoplastic.

Suitable silane compounds are those of the general formula(X—(CH₂)_(n))_(k)—Si—(O—C_(m)H_(2m+1))_(4−k)where the substituents are:

n is a whole number from 2 to 10, preferably from 3 to 4

m is a whole number from 1 to 5, preferably from 1 to 2

k is a whole number from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane,aminobutyltrimethoxysilane, aminopropyltriethoxysilane,aminobutyltriethoxysilane, and also the corresponding silanes whichcontain a glycidyl group as substituent X.

The amounts generally used of the silane compounds for surface coatingare from 0.05 to 5% by weight, preferably from 0.5 to 1.5% by weight,and in particular from 0.8 to 1% by weight (based on E).

Acicular mineral fillers are also suitable.

For the purposes of the invention, acicular mineral fillers are mineralfillers with very pronounced acicular character. An example which may bementioned is acicular wollastonite. The L/D (length/diameter) ratio ofthe mineral is preferably from 8:1 to 35:1, with preference from 8:1 to11:1. If appropriate, the mineral filler may have been pretreated withthe abovementioned silane compounds; however, this pretreatment is notessential.

Other fillers which may be mentioned are kaolin, calcined kaolin,wollastonite, talc, and chalk.

As component E), the inventive thermoplastic molding compositions maycomprise conventional processing aids, such as stabilizers, oxidationretarders, stabilizers to counter decomposition due to heat or due toultraviolet light, lubricants, mold-release agents, colorants, such asdyes and pigments, nucleating agents, plasticizers, etc.

Examples which may be mentioned of oxidation retarders and heatstabilizers are sterically hindered phenols and/or phosphites,hydroquinones, aromatic secondary amines, such as diphenylamines,various substituted members of these groups, and mixtures of these inconcentrations of up to 1% by weight, based on the weight of thethermoplastic molding compositions.

UV stabilizers which may be mentioned, and are generally used in amountsof up to 2% by weight, based on the molding composition, are varioussubstituted resorcinols, salicylates, benzotriazoles, and benzophenones.

Colorants which may be added are inorganic pigments, such as titaniumdioxide, ultramarine blue, iron oxide, and carbon black, and alsoorganic pigments, such as phthalocyanines, quinacridones and perylenes,and also dyes, such as nigrosine and anthraquinones.

Nucleating agents which may be used are sodium phenylphosphinate,alumina, silica, and preferably talc.

Other lubricants and mold-release agents are usually used in amounts ofup to 1% by weight. Preference is given to long-chain fatty acids (e.g.stearic acid or behenic acid), salts of these (e.g. calcium stearate orzinc stearate) or montan waxes (mixtures of straight-chain saturatedcarboxylic acids having chain lengths of from 28 to 32 carbon atoms), orcalcium montanate or sodium montanate, or low-molecular-weightpolyethylene waxes or low-molecular-weight polypropylene waxes.

Examples of plasticizers which may be mentioned are dioctyl phthalates,dibenzyl phthalates, butyl benzyl phthalates, hydrocarbon oils andN-(n-butyl)benzene-sulfonamide.

The inventive molding compositions may also comprise from 0 to 2% byweight of fluorine-containing ethylene polymers. These are polymers ofethylene with a fluorine content of from 55 to 76% by weight, preferablyfrom 70 to 76% by weight.

Examples of these are polytetrafluoroethylene (PTFE),tetrafluoroethylene-hexafluoropropylene copolymers andtetrafluoroethylene copolymers with relatively small proportions(generally up to 50% by weight) of copolymerizable ethylenicallyunsaturated monomers. These are described, for example, by Schildknechtin “Vinyl and Related Polymers”, Wiley-Verlag, 1952, pages 484-494 andby Wall in “Fluoropolymers” (Wiley Interscience, 1972).

These fluorine-containing ethylene polymers have homogeneousdistribution in the molding compositions and preferably have a particlesize d₅₀ (numeric average) in the range from 0.05 to 10 μm, inparticular from 0.1 to 5 μm. These small particle sizes can particularlypreferably be achieved by the use of aqueous dispersions offluorine-containing ethylene polymers and the incorporation of theseinto a polyester melt.

The inventive thermoplastic molding compositions may be prepared bymethods known per se, by mixing the starting components in conventionalmixing apparatus, such as screw extruders, Brabender mixers or Banburymixers, and then extruding them. The extrudate may be cooled andcomminuted. It is also possible to premix individual components and thento add the remaining starting materials individually and/or likewise ina mixture. The mixing temperatures are generally from 230 to 290° C.

In another preferred method of operation, components B), and also, ifappropriate, C)/D)/E) may be mixed with a polyester prepolymer,compounded, and pelletized. The resultant pellets are thensolid-phase-condensed, continuously or batchwise, under an inert gas, ata temperature below the melting point of component A) until the desiredviscosity has been reached.

The inventive thermoplastic molding compositions feature goodflowability together with good mechanical properties.

In particular, the processing of the individual components (withoutclumping or caking) is problem-free and possible in short cycle times,permitting in particular an application as thin-walled components.

The use for an improved-flow polyester can be applicable to almost anyinjection molding application. The improved flow permits use of a lowermelt temperature and can therefore lead to a marked lowering of theentire cycle time for the injection molding process (lowering of themanufacturing costs for an injection molding!). The injection pressuresneeded during processing are moreover lower, therefore requiring a lowertotal locking force for the injection mold, and less capital expenditureon the injection molding machine.

Alongside the improvements in the injection molding process, thelowering of the melt viscosity can lead to marked advantages in theactual design of the molding. For example, injection molding can be usedto produce thin-walled applications which, for example, could nothitherto be produced using filled polyester grades. Similarly, the useof reinforced but free-flowing polyester grades in existing applicationscan reduce wall thicknesses and therefore reduce component weights.

These materials are suitable for the production of fibers, films, andmoldings of any type, in particular for applications as plugs, switches,housing parts, housing covers, headlamp bezels, shower heads, filtings,smoothing irons, rotary switches, stove controls, fryer lids, doorhandles, (rear) mirror housing, wipers for windshields or for rearwindows, sheathing for optical conductors.

Electrical and electronic applications which can be produced using theimproved-flow polyesters are plugs, plug components, plug connectors,cable harness components, cable mounts, cable mount components,three-dimensionally injection-molded cable mounts, electrical connectorelements, mechatronic components, and optoelectronic components.

Possible uses in automobile interiors are dashboards, steering columnswitches, seat components, headrests, center consoles, gearboxcomponents, and door modules, and possible automobile exteriorcomponents are door handles, headlamp components, exterior mirrorcomponents, windshield washer components, windshield washer protectivehousings, grilles, roof rails, sunroof frames, and exterior bodyworkparts.

Possible uses of the improved-flow polyester in the kitchen andhousehold sector are production of components for kitchen equipment,e.g. fryers, smoothing irons, buttons, and also garden and leisuresector applications, such as components for irrigation systems or gardenequipment.

In the medical technology sector, it becomes simpler to produce inhalerhousings and components of these via improved-flow polyesters.

The morphology of selected compounded materials was studied viatransmission electron micrographs. Good dispersion of the particles inthe blend is seen. Particle sizes of from 20 to 500 nm were observed.

EXAMPLES

Component A/1:

Polybutylene terephthalate with a viscosity number VN of 130 ml/g andwith a carboxy end group content of 34 meq/kg (Ultradure B 4500 fromBASF AG) (VN measured in 0.5% strength by weight solution ofphenol/o-dichlorobenzene, 1:1 mixture at 25° C.).

Component A/2:

Polyethylene terephthalate with a viscosity number VN of 74.5 ml/g

Preparation Specification for Polycarbonates B)

General Operating Specification:

As shown in table 1, equimolar amounts of the polyhydric alcohol anddiethyl carbonate were mixed in a three-necked flask equipped withstirrer, reflux condenser, and internal thermometer, and 250 ppm ofcatalyst (based on the amount of alcohol) were added. The mixture wasthen heated with stirring to 100° C., and in the experiment indicatedby * to 140° C., and stirred for 2 h at this temperature. Evaporativecooling caused by the monoalcohol liberated reduced the temperature ofthe reaction mixture here as the reaction proceeded. The refluxcondenser was now replaced by an inclined condenser, ethanol was removedby distillation, and the temperature of the reaction mixture wasincreased slowly to 160° C.

The ethanol removed by distillation was collected in a cooledround-bottomed flask, and weighed, and the conversion was thusdetermined as a percentage based on the full conversion theoreticallypossible (see table 1).

The reaction products were then analyzed by gel permeationchromatography, the eluent being dimethylacetamide and the standardbeing polymethyl methacrylate (PMMA).

TABLE 1 Amount of ethanol distillate, based on Visc. complete conversionMolecular 23° C. OH number Alcohol Catalyst [mol %] weight M_(w)/M_(n)[mPas] [mg KOH/g] B1/1 TMP × 3 EO K₂CO₃ 90 5907/2154 1810 300 B1/2 Gly ×5 EO K₂CO₃ 90 8230/2898 1570 203 TMF {circumflex over (=)}trimethylolpropane EO {circumflex over (=)} ethylene oxide Gly{circumflex over (=)} glycerolComponent B2):

TABLE 2 Mn Mw OH number Acid number Monomers (g/mol) (g/mol) (mg KOH/g)(mg KOH/g) B 2 Terephthalic 900 2390 416 0 acid and glycerolPreparation of B2:

1589 g (8.19 mol) of dimethyl terephthalate and 628 g (6.83 mol) ofglycerol were used as initial charge in a 5 l glass flask equipped withstirrer, internal thermometer, gas inlet tube, reflux condenser, andvacuum connection with cold trap. 4.4 g of di-n-butyltin oxide,commercially available as Fascat® 4201, were added, and the mixture washeated with the aid of an oil bath to an internal temperature of 140° C.A reduced pressure of 50 mbar was applied in order to remove waterformed during the reaction. The reaction mixture was kept for 34 hoursat the stated temperature and the stated pressure. It was then cooled toroom temperature, giving 1750 g of hyperbranched polyester in the formof a clear, high-viscosity liquid. The analytical data are given intable 2.

Component C):

A graft polymer with a core/shell ratio of 60:40; the core beingcomposed of

98% by weight of n-butyl acrylate and

2% by weight of dicyclopentadienyl acrylate, and

the shell being composed of

75% by weight of styrene,

25% by weight of acrylonitrile.

Component D):

SAN copolymer composed of 67% by weight of styrene and 33% by weight ofacrylonitrile with a VN of 80 ml/g, measured at 23° C. on a 0.5%strength by weight solution in DMF to DIN 53726.

Component E/1:

Glass fibers with an average diameter of 10 μm.

Component E/2:

Pentaerythritol tetrastearate

Preparation of Molding Compositions

Components A) to E) were blended in a twin-screw extruder at from 250 to260° C., and extruded into a waterbath. After pelletization and drying,test specimens were injection molded and tested.

The pellets were injection molded to give dumbbell specimens to ISO527-2, and a tensile test was carried out. Impact resistance wasmoreover determined to ISO 179-2, and viscosity (solvent for PBT to DIN53728: phenol/1,2-dichlorobenzene (1:1) ISO 1628), MVR (ISO 1133), andflow behavior were tested.

The inventive compositions and the results of the measurements are givenin table 3.

TABLE 3 1c 2 3 4 5 6 7 Component A/1 [% by weight] 41.2 40.2 40.2 40.240.2 40.2 40.2 A/2 [% by weight] 10 10 10 10 10 10 10 B1/1 [% by weight]— — — — — 1 2 B1/2 [% by weight] — — — 1 2 — — B2 [% by weight] — 1 2 —— — — C [% by weight] 9 9 9 9 9 9 9 D [% by weight] 9 9 9 9 9 9 9 E/1 [%by weight] 30 30 30 30 30 30 30 E/2 [% by weight] 0.8 0.8 0.8 0.8 0.80.8 0.8 VN [g/l] 101 95 91 95.7 85.2 94 88 MVR (275° C.; 2.16 kg) 43 87129 53.7 79 61 108 Mechanic properties: Modulus of elasticity [N/mm]8639 8597 8602 8524 8211 8561 8286 Tensile strain at break [%] 2.4 2.11.7 2.4 2.1 2.3 2 Stress at max [N/mm] 100 97 91 — — — — Charpy impactresistance 45 38 33 38 34 37 29 [kJ/m²] Flow spiral 260° C./80° C. 2 mm43 51 59 51 59 53.6 63

1. A thermoplastic molding composition, comprising A) from 10 to 98.99%by weight of at least one thermoplastic polyester, B) from 0.01 to 20%by weight of B1) at least one hyperbranched polycarbonate having an OHnumber of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, Part2),and B1 ) has a glass transition temperature Tg of from −80°C. to140°C. or B2) at least one hyperbranched A_(x)B_(y) polyester and B2)has a glass transition temperature T_(g) of from −50°C. to 140°C., or amixture of B1) and B2), wherein A_(x) and B_(y) are different monomersand indices x and y are the number of functional groups present in A andB, wherein x is at least 1.1 and y is at least 2.1, wherein B2) has anOH number of from 0 to 600 mg KOH/g and a COOH number of from 0 to 600mg KOH/g, wherein a degree of branching of both B1) and B2) is from 10to 99.9%, and wherein B1) and B2) have both structural and molecularnon-uniformity; C) from 1 to 60% by weight of at least one graftpolymer, comprising, c₁) from 20 to 80% by weight of a graft basecomprising an elastomeric polymer based on alkyl acrylates having from 1to 8 Carbon atoms in the alkyl moiety and having a glass transitiontemperature below 10° C. c₂) from 20 to 80% by weight of a graftcomposed of c₂₁) from 60 to 95% by weight of styrene or of substitutedstyrenes of the general formula I

where R is an alkyl radical having from 1 to 8 carbon atoms or ahydrogen atom, and R¹ is an alkyl radical having from 1 to 8 carbonatoms, and n is 1, 2, or 3, and c₂₂) from 5 to 40% by weight of at leastone unsaturated nitrile, D) from 0 to 60% by weight of a copolymercomprising, d₁) from 60 to 95% by weight of styrene or of substitutedstyrenes of the general formula I, or a mixture of these, d₂) from 5 to40% by weight of at least one unsaturated nitrile, E) from 0 to 60% byweight of other additives, where the total of the percentages by weightof components A) to E) is 100%.
 2. The thermoplastic molding compositionaccording to claim 1, wherein the thermoplastic molding compositioncomprises component B1 and B1)has a number-average molar mass M_(n) offrom 100 to 15 000 g/mol.
 3. The thermoplastic molding compositionaccording to claim 1, wherein the thermoplastic molding compositioncomprises component B1 and B1) has a viscosity (mPas) at 23° C. (to DIN53019) of from 50 to 200
 000. 4. The thermoplastic molding compositionaccording to claim 1, wherein the thermoplastic molding compositioncomprises component B2 and B2) has a number-average molar mass M_(n) offrom 300 to 30 000 g/mol.
 5. The thermoplastic molding compositionaccording to claim 1, wherein the thermoplastic molding compositioncomprises components B1) and B2) and wherein the ratio of the componentsB1) : B2) is from 1:20 to 20:1.
 6. The thermoplastic molding compositionaccording to claim 1, comprising component A) from 30 to 97.99% byweight component B) from 0.01 to 50% by weight component C) from 1 to60% by weight component D) from 1 to 45% by weight.
 7. The thermoplasticmolding composition according to claim 1, wherein the thermoplasticmolding composition comprises from 1 to 45% by weight of component D)based on the entirety of components A) to E).
 8. The thermoplasticmolding composition according to claim 1, wherein the thermoplasticmolding composition comprises component E) and wherein component E) isat least one selected from the group consisting of a processing and, astabilizer, an oxidation retarder, a heat stabilizer, an ultravioletlight stabilizer, a lubricant, a mold-release agent, a colorant, a dye,a pigment, a filler, a nucleating agent and a plasticizer.
 9. Thethermoplastic molding composition according to claim 1, wherein thethermoplastic molding composition comprises component E) and whereincomponent E) is at least one ester or amide of saturated or unsaturatedaliphatic carboxylic acids having from 10 to 40 carbon atoms withsaturated aliphatic alcohols or amines having from 2 to 40 carbon atoms.10. The thermoplastic molding composition according to claim 1, whereinthe maximum amount of B) is 10% by weight.
 11. The thermoplastic moldingcomposition according to claim 1, wherein the degree of branching ofboth B1) and B2) is from 20 to 99%.
 12. The thermoplastic moldingcomposition according to claim 1, wherein the degree of branching ofboth B1) and B2) is from 20 to 95%.
 13. The thermoplastic moldingcomposition according to claim 1, wherein the thermoplastic moldingcomposition comprises component E) and wherein component E) is at leastone filler selected from the group consisting of carbon fiber, glassfiber, glass bead, amorphous silica asbestos, calcium silicate, calciummetasilicate, magnesium carbonate, kaolin, chalk, powdered quartz, mica,barium sulphate, feldspar, aramid fiber and potassium titanate fiber.14. The thermoplastic molding composition according to claim 13, whereinthe filler is surface-pretreated with a silane compound.
 15. A methodfor production of fibers, foils, or moldings comprising adding thethermoplastic molding composition according to claim 1 to a fiber, foilor molding formulation.
 16. A fiber, a foil, or a molding of any type,obtainable from the thermoplastic molding composition according to claim1.